*{
    margin: 0px;
    padding: 0px;
}
ul{
    height: 160px;
    float: left;
    width: auto;
    margin-left: 100px;
    margin-top: 100px;
    border: 3px solid #C8C8C8;
    li{
        list-style: none;
        float:left;
        position: relative;
        width: 270px;
        height: 160px;
        .cover{
            position: absolute;
            left: 0px;
            top: 0px;
            background: #000;
            width: 100%;
            height: 100%;
            opacity: 0.5;
        }
        img{
            width: 270px;
            height: 160px;
            float: left;
        }
    }
}



